PROJECT SUMMARY Anxiety disorders are the most common class of mental illness in children, affecting up to 30% of individuals prior to their eighteenth birthday. Children who develop an anxiety disorder often experience significant family, social, and academic impairments and are at increased risk for developing additional psychiatric disorders as adults. Although successful treatment has been linked to benefits that extend into adulthood, many children remain highly symptomatic even with the best available treatments. New early interventions are clearly needed for this highly prevalent condition. The mission statement of the National Institute of Mental Health offers a general approach to finding new treatments: ?to understand mind, brain, and behavior, and thereby to reduce the burden of mental illness through research.? Functional brain networks are collections of brain regions with a common function. Understanding pathology at the level of functional brain networks holds enormous promise for unlocking the development, etiology, and treatment of mental illnesses such as pediatric anxiety disorders. With this framework in mind, the purpose of this Mentored Patient-Oriented Career Development Award (K23) is to enable the candidate to develop a research program investigating alterations in functional brain networks in childhood anxiety disorders. The applicant's long-term goal is to use functional brain networks to predict longitudinal course, treatment response, and develop new treatments for pediatric anxiety disorders. To help achieve this goal, the training plan in this application addresses the applicant's need for training in clinical developmental psychopathology research. Training and mentorship are provided in: 1) clinical assessments of children for research purposes, 2) understanding emotional and cognitive development, 3) pediatric neuroimaging, 4) longitudinal study design and analysis, and 5) treatment development. The research plan for this project is closely linked to the training plan and includes the assistance of a multidisciplinary team of mentors and consultants. The research proposal tests the hypothesis that alterations in one particular functional network, the ventral attention network (VAN), are associated the development of anxiety disorders. General alterations in the VAN are proposed to result in anxiety by increasing the orientation of attention to threatening stimuli. To test these hypotheses, children ages 8-12 years with and without anxiety disorders are assessed twice, 24 months apart, using neuroimaging and behavioral methods in a prospective design. Data from this study will be used to inform an application for a more definitive R01 project that maps developmental relations between the ventral attention network and development of anxiety in young at-risk children before the onset of anxiety disorders. Results from this application are expected to have immediate treatment implications, by determining whether treatment development should target the ventral attention network. This proposal also develops a framework for examining additional functional brain network pathophysiology associated with pediatric anxiety disorders.